Diaminostilbene derivatives

ABSTRACT

The following 4,4′-bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid derivative is well soluble in water:  
                 
 
in which each of R 11  and R 12  is hydrogen, or a specifically substituted or unsubstituted alkyl group; each of R 21  and R 22  is hydrogen, a specifically substituted or unsubstituted alkyl group, a specifically substituted or unsubstituted aryl group; M is hydrogen, alkali metal, alkaline earth metal, ammonium, or pyridinium.

FIELD OF THE INVENTION

The present invention relates to a4,4′-bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid derivativewhich is favorably employable in an aqueous fluorescent brighteningsolution, an aqueous photographic silver halide emulsion, an aqueoussolution for processing a photographic silver halide-containingmaterial. The invention further relates to use of the4,4′-bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid derivativefor brightening a variety of materials with fluorescence.

BACKGROUND OF THE INVENTION

Tamehiko Noguchi describes in Journal of Society of Organic SyntheticChemistry (Yuki Gosei Kagaku Kyoukaishi), vol. 19, p. 920 (1961) andvol. 20, p. 64 (1962) that4,4′-bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid derivativesare useful as fluorescent brightening agents.

U.S. Pat. No. 2,875,058, No. 2,933,390, and No. 2,945,762 describe4,4′-bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid derivativesare employable as additives for a photographic silver halide emulsion.

German Patent (DE) No. 1,945,316 discloses4,4′-bis-(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid derivativeswhich show high fluorescent brightening effect on cellulose fibers. Thedisclosed derivatives have a sulfoethylamine substituent group on the2-position of its triazine ring and additionally a morpholine oralkanolamine substituent group on the 4-position. Examples of thealkanolamines are monoethanolamine, methylethanolamine, diethanolamine,isopropanolamine, and diisopropanolamine.

The 4,4′-bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acidderivatives to be employed in the form of aqueous solutions such asphotographic silver halide emulsions and aqueous solutions forprocessing photographic silver halide-containing material are preferablywell soluble in water or an aqueous solution. In more detail, thederivatives should be rapidly dissolved in an aqueous medium and thenshould be hardly deposited during the storage of the aqueous solution.

Japanese Patent Provisional Publications No. 6-329,936 and No. 6-332,127disclose 4,4′-bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acidderivatives which are employable as fluorescent brightening agents foran aqueous solution for processing photographic silver halide material.The disclosed derivatives have high solubility in the aqueous solutionand are hardly deposited even when the processing solution is kept atlow temperatures. The latter 6-332,127 publication indicates that apreferred compound is such derivative that the triazine ring issubstituted on its 2-position with ethylamine having a sodium sulfonatesalt [therefore, four sodium sulfonate groups are introduced into thederivative] and further substituted on its 4-position with analkanolamine (e.g., 2-methyethanolamine).

SUMMARY OF THE INVENTION

According to the studies of the present inventors, the known4,4′-bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid derivativesdo not show satisfactory solubility in an aqueous medium from theviewpoints of practical use of the fluorescent brightening agent.

It is an object of the present invention to provide4,4′-bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid derivativeswhich show increased solubility in an aqueous medium.

As a result of further studies performed by the inventors, it has beendiscovered that the desired high solubility is attained by introducinginto the 4-position of the triazine ring of the4,4′-bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid derivativean amino group having an alkylene substituent of 2 to 8 carbon atoms inwhich the alkylene substituent has a hydroxyl group or a hydroxyalkylgroup of 1 to 3 carbon atoms as a substituent or has an interveningether bonding.

Accordingly, the present invention resides in a4,4′-bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid derivativehaving the following formula (1):

in which

-   -   each of R¹¹ and R¹² independently is a hydrogen atom, an alkyl        group having 1 to 20 carbon atoms, or an alkyl group having 1 to        20 carbon atoms which has one or more substituents selected from        the group consisting of hydroxyl, sulfo, and alkoxy;    -   R²¹ is a hydrogen atom, an alkyl group having 1 to 20 carbon        atoms, an alkyl group having 1 to 20 carbon atoms which has one        or more substituents selected from the group consisting of        hydroxyl, sulfo, and alkoxy, an aryl group having 6 to 20 carbon        atoms, an aryl group having 6 to 20 carbon atoms which has one        or more substituents selected from the group consisting of        hydroxyl, carboxyl, alkyl, or alkoxy, or a group represented by        the formula of -L¹-CH₂OH wherein L¹ is an alkylene group having        2 to 8 carbon atoms which has one or more substituents selected        from the group consisting of hydroxyl and hydroxylalkyl having 1        to 3 carbon atoms or which has an intervening ether bonding;    -   R²² is a hydrogen atom, an alkyl group having 1 to 20 carbon        atoms, an alkyl group having 1 to 20 carbon atoms which has one        or more substituents selected from the group consisting of        hydroxyl, sulfo, and alkoxy, an aryl group having 6 to 20 carbon        atoms, an aryl group having 6 to 20 carbon atoms which has one        or more substituents selected from the group consisting of        hydroxyl, carboxyl, alkyl, or alkoxy, or a group represented by        the formula of -L²-CH₂OH wherein L² is an alkylene group having        2 to 8 carbon atoms which has one or more substituents selected        from the group consisting of hydroxyl and hydroxylalkyl having 1        to 3 carbon atoms or which has an intervening ether bonding; and    -   M is a hydrogen atom, an alkali metal atom, an alkaline earth        metal atom, ammonium group, or pyridinium group.

The 4,4′-bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acidderivatives of the invention is included in the general formula (SR) ofthe diaminostilbene compound for fluorescent brightening agent which isdisclosed in the aforementioned Japanese Patent Provisional PublicationNo. 6-332127. However, the specifically defined4,4′-bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid derivativesof the invention are not described in the publication.

The present invention further resides in an aqueous solution containinga 4,4′-bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid derivativeof the above-mentioned formula (1).

The invention furthermore resides in a method of brightening a surfaceof material with fluorescence which comprises applying a4,4′-bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid derivativeof the formula (1) onto the surface of material.

DETAILED DESCRIPTION OF THE INVENTION

The 4,4′-bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acidderivatives of the invention is represented, as mentioned above, by thefollowing formula (1):

In the formula (1), an alkyl group for R¹¹ and R¹² has 1 to 20 carbonatoms, preferably 1 to 8 carbon atoms, more preferably 1 to 4 carbonatoms. The alkyl group can be a straight chain alkyl group, a branchedchain alkyl group, or a cyclic alkyl group. The alkyl group can have oneor more substituent groups. Examples of the substituent groups include ahydroxyl group, a sulfo group, and an alkoxy group. The alkoxy grouppreferably has such alkyl group as mentioned above.

Examples of the alkyl groups for R¹¹ and R¹² include methyl, ethyl,n-propyl, isopropyl, n-octyl, 2-hydroxyethyl, 3-hydroxypropyl,2-hydroxypropyl, 2-sulfoethyl, 2-methoxyethyl, 2-(2-hydroxyethoxy)ethyl,2-[2-(2-hydroxyethoxy)ethoxy]ethyl; and2-(2-[2-(2-hydroxyethoxy)-ethoxy]ethoxy)ethyl.

Each of R¹¹ and R¹² preferably is hydrogen, methyl, ethyl, n-propyl,n-butyl, or 2-sulfoethyl, and more preferably hydrogen, methyl, ethyl,or 2-sulfoethyl. Most preferred is hydrogen or atom.

Examples of the alkyl groups for R²¹ and R²² are those describedhereinbefore for R¹¹ and R¹². Preferred examples of R²¹ and R²² includehydrogen, methyl, ethyl, n-propyl, isopropyl, 2-hydroxyethyl,3-hydroxypropyl, 2-hydroxypropyl, 2,3-dihydroxypropyl, 2-sulfoethyl,2-(2-hydroxyethoxy)ethyl, and 2-[2-(2-hydroxyethoxy)ethoxy]ethyl. Morepreferred examples include hydrogen, methyl, ethyl, isopropyl,2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 2,3-dihydroxpropyl,and 2-(2-hydroxyethoxy)ethyl. Most preferred are hydrogen and methyl.

The aryl group for R²¹ and R²² has 6 to 20 carbon atoms, preferably 6 to10 carbon atoms, more preferably 6 to 8 carbon atoms. The aryl group canhave one or more substituents. Examples of the substituents include ahydroxyl group, a carboxyl group, an alkyl group, and an alkoxy group.The alkyl group and alkoxy group of the substituent can be the same asthose described hereinbefore for R¹¹and R¹². Examples of the substitutedand unsubstitued aryl groups for R²¹ and R²² include phenyl, naphthyl,4-hydroxyphenyl, 3,5-dicarboxyphenyl, 4-methoxyphenyl, and3-isopropylphenyl. The aryl group preferably is phenyl or4-hydroxyphenyl.

The alkylene group for L¹ and L² is an alkylene group having 2 to 8carbon atoms which has, as a substituent, a hydroxyl group or ahyroxyalkyl group having 1 to 3 carbon atoms. Otherwise, the alkylenegroup has an ether bonding which intervenes the alkylene chain at anoptional position.

Preferred examples of the alkylene group for L¹ and L² include those ofthe following formulas 1) to 5):

More preferred are those of the above-mentioned formulas 1) to 4),namely, alkylene groups having one or more hydroxyl substituent groups.Most preferred are those of the formulas 1) and 4).

Other preferred examples of the alkylene group for L¹ and L² includethat represented by the following formula (2):—(CH₂CH₂O)_(n)CH₂—  (2)in which n is an integer of 1 to 3, preferably 1 or 2. Most preferably,n is 1.

In the formula (1), M is a hydrogen atom, an alkali metal atom, analkaline earth metal atom, ammonium group, or pyridinium group. Examplesof the alkali metal atoms include Li, Na, K, Rb, Cs, and Fr. Examples ofthe alkaline earth metal atoms include Ca, Sr, Ba, and Ra. Preferred areNa and K. Examples of the ammonium groups include triethylammonium andtetrabutylammonium.

Representative examples of the formula (1) of the invention areillustrated below:

When the alkylene group for L¹ or L² of the formula (1) has a hydroxylor hydroxyalkyl substituent and contains in its structure two or moreasymmetric carbon atoms to which the substituent is attached, there area plurality of stereoisomers having the same formula. Any of the isomerscan be employed singly or in combination.

The 4,4′-bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acidderivative of the formula (1) can be prepared by referring to thedescriptions of Journal of Society of Organic Synthetic Chemistry, vol.17, page 528 (1959) [written by Hirotsugu Matsui] and Japanese PatentNo. 2,618,748.

In more detail, the compound of the formula (1) can be prepared by thesteps of reacting a diaminostilbene derivative with cyanuric chloride,reacting the resulting 4,4′-bistriazinylaminostilbene derivative withtaurine, and finally reacting the resulting product withhydroxyalkylamine. Otherwise, a process starting from adialkylaminostilbene derivative can be adopted.

The reaction can be performed in a solvent such as water or an organicsolvent (e.g., alcohol, ketone, ether or amide). Water andwater-miscible organic solvents are preferred. The reaction solvent canbe a mixture of appropriate solvents. Preferred is an aqueous acetonesolvent. Generally, a base is employed in the reaction. Examples of thebases include organic bases such as triethylamine, pyridine, and1,8-diazabicyclo[5,4,0]-7-undecene, and inorganic bases such as sodiumhydroxide, potassium hydroxide, sodium carbonate, potassium carbonate,sodium hydrogen carbonate, and sodium hydride. The inorganic bases suchas sodium hydroxide, potassium hydroxide, sodium carbonate and potassiumcarbonate are preferably employed. The reaction is generally performedat a temperature in the range of −20° C. to 120° C., preferably −10° C.to 90° C. In more detail, the reaction in the first step is preferablyperformed at a temperature of −10° C. to 10° C.; the reaction in thesecond step is preferably performed at a temperature of 0° C. to 40° C.;and the reaction in the third is preferably performed at a temperatureof 50° C. to 90° C.

The present invention is further described by the followingnon-restricting examples.

EXAMPLE 1

The aforementioned compound (I-1) of the invention was preparedaccording to the following scheme:

1) Preparation of Compound 3

In a three-necked flask were placed 103.5 g of Compound 1 and 680 mL ofacetone. The content was chilled to −5° C. by placing the flask in anice-acetone bath. To the chilled content was dropwise added understirring an aqueous solution of 101.9 g of Compound 2 and 58.3 g ofsodium carbonate in 960 mL of water for a period of one hour. Thetemperature of the flask content increased to −1° C. After the dropwiseaddition was complete, the ice-acetone bath was removed, and the flaskcontent was further stirred for one hour. The precipitated crystallineproduct was collected on filter by suction, to obtain the desiredCompound 3. Thus obtained product was submitted to the next step withoutdrying and purifying.

2) Preparation of Compound 4

In a three-necked flask were placed the Compound 3 obtained above and1.9 L of water. The content was stirred on a water bath, and to thestirred content was added 68.8 g of taurine. Further, an aqueoussolution of 58.3 g of sodium carbonate in 275 mL of water was dropwiseadded for a period of one hour under stirring. After the dropwiseaddition was complete, the water bath was removed and the stirring wascontinued for 3 hours. To the stirred content was added 550 g of sodiumchloride, and the stirred is continued for one hour. The precipitatedcrystalline product was collected on filter by suction, to obtain thedesired Compound 4. Thus obtained product was submitted to the next stepwithout drying and purifying.

3) Preparation of Compound (I-1)

In a three-necked flask were placed the Compound 4 obtained above and825 mL of water. The content was stirred at room temperature, and to thestirred content was dropwise added 125.3 g of Compound 5 at roomtemperature, while the stirring was continued. After the dropwiseaddition was complete, the content was stirred at an inner temperatureof 85° C. for 3 hours. The reaction mixture was concentrated in a rotaryevaporator. When the residual content reduced to approximately 800 mL, acrystalline product precipitated and the concentration procedure wasstopped. The content was then stirred with chilling with ice, and theprecipitated crystalline product was collected on filter by suction. Tothus obtained crystalline product was added 1.5 L of methanol, and theresulting mixture was stirred for one hour under reflux. The reactionmixture was cooled to room temperature, and subjected to filtrationusing suction, to obtain 206.0 g (yield: 72%) of the desired Compound(I-1).λ_(max)(H₂O)=346.3 nm(ε=4.83×10⁴)

The obtained product of Compound (I-1) had a purity of 96.0% (determinedby liquid chromatography).

The liquid chromatography was carried out under the followingconditions:

-   -   Column: TSK-gel ODS-80 (available from Toso Co., Ltd.)    -   Eluents:        -   Eluent A (20 mL of PIC A reagent, available from Waters            Corp., was added to 1 L of water)        -   Eluent B (20 mL of PIC A reagent was added to a mixture of            800 mL of methanol and 200 mL of water)        -   Eluent A/Eluent B=50/50 (0 min.)→0/100 (35 min.)    -   Detecting wavelength: 346 nm        The purity was determined from a peak area of the        chromatographic chart.

EXAMPLE 2

The aforementioned compound (I-4) of the invention was preparedaccording to the following scheme:

In a three-necked flask were placed Compound 4 which had been preparedin the same manner as in Example 1 (i.e., same scale and same syntheticprocess) and 825 mL of water. The content was stirred at roomtemperature, and to the stirred content was dropwise added 144.6 g ofCompound 6 at room temperature for 10 minutes, while the stirring wascontinued. After the dropwise addition was complete, the content wasstirred at an inner temperature of 85° C. for 3 hours. The reactionmixture was concentrated in a rotary evaporator. When the residualcontent reduced to approximately 900 mL, a crystalline productprecipitated and the concentration procedure was stopped. The contentwas then stirred with chilling with ice, and the precipitatedcrystalline product was collected on filter by suction. To thus obtainedcrystalline product was added 1.5 L of methanol, and the resultingmixture was stirred for one hour under reflux with heating. The reactionmixture was cooled to room temperature, and subjected to filtrationusing suction, to obtain 216.5 g (yield: 78%) of the desired Compound(I-4).λ_(max)(H₂O)=346.5 nm(ε=4.77×10⁴)

The obtained product of Compound (I-4) had a purity of 94.4% (determinedby liquid chromatography which was performed in the same manner as inExample 1).

EXAMPLE 3

The aforementioned compound (I-11) of the invention was preparedaccording to the following scheme:

In a three-necked flask were placed Compound 4 which had been preparedin the same manner as in Example 1 (i.e., same scale and same syntheticprocess) and 825 mL of water. The content was stirred at roomtemperature, and to the stirred content was dropwise added 144.4 g ofCompound 7 at room temperature for 10 minutes, while the stirring wascontinued. After the dropwise addition was complete, the content wasstirred at an inner temperature of 85° C. for 3 hours. The reactionmixture was concentrated in a rotary evaporator. When the residualcontent reduced to approximately 800 mL, a crystalline productprecipitated and the concentration procedure was stopped. The contentwas then stirred with chilling with ice, and the precipitatedcrystalline product was collected on filter by suction. To thus obtainedcrystalline product was added 1.5 L of methanol, and the resultingmixture was stirred for one hour under reflux with heating. The reactionmixture was cooled to room temperature, and subjected to filtrationusing suction, to obtain 249.7 g (yield: 85%) of the desired Compound(I-11).λ_(max)(H₂O)=354.5 nm(ε=4.92×10⁴)

The obtained product of Compound (I-11) had a purity of 97.3%(determined by liquid chromatography which was performed in the samemanner as in Example 1).

EXAMPLE 4

The aforementioned compound (I-22) of the invention was preparedaccording to the following scheme:

In a three-necked flask were placed Compound 4 which had been preparedin the same manner as in Example 1 (i.e., same scale and same syntheticprocess) and 825 mL of water. The content was stirred at roomtemperature, and to the stirred content was dropwise added 268.5 g ofCompound 8 at room temperature for 10 minutes, while the stirring wascontinued. After the dropwise addition was complete, the content wasstirred at an inner temperature of 85° C. for 3 hours. The reactionmixture was concentrated in a rotary evaporator. When the residualcontent reduced to approximately 900 mL, a crystalline productprecipitated and the concentration procedure was stopped. The contentwas then stirred with chilling with ice, and the precipitatedcrystalline product was collected on filter by suction. To thus obtainedcrystalline product was added 1.5 L of methanol, and the resultingmixture was stirred for one hour under reflux with heating. The reactionmixture was cooled to room temperature, and subjected to filtrationusing suction, to obtain 302.9 g (yield: 88%) of the desired Compound(I-22).λ_(max)(H₂O)=348.6 nm(ε=4.36×10⁴)

The obtained product of Compound (I-22) had a purity of 96.1%(determined by liquid chromatography which was performed in the samemanner as in Example 1).

EXAMPLES 5 and 6

The aforementioned Compound (I-2) and compound (I-12) were prepared inmanner similar to those described in Examples 1 to 4.

EXAMPLE 7

Compounds I-1, I-2, I-4, I-11, I-12, and I-22 obtained above, and theComparison Compounds a, b, c and d were subjected to evaluation ofsolubility in water.

Water (100 mL) was added to 20 g of each sample, and the mixture wasplaced on a warm bath (at 40° C.), and stirred using a magnetic stirrer,so that the added sample was dissolved in the warm water. Then, theobtained aqueous solution was placed on an ice bath under stirring.

The conditions of the aqueous mixture in the dissolving procedure andthe aqueous solution on the ice bath were observed for evaluatingsolubility in water at 40° C. and 0° C. The results are seen in thefollowing Table. Compound Solubility at 40° C. Solubility of 0° C. Comp.I-1 dissolved within 120 sec. No deposition within 180 sec. Comp. I-2dissolved within 150 sec. No deposition within 180 sec. Comp. I-4dissolved within 150 sec. No deposition within 180 sec. Comp. I-11dissolved within 120 sec. No deposition within 180 sec. Comp. I-12dissolved within 140 sec. No deposition within 180 sec. Comp. I-4dissolved within 140 sec. No deposition within 180 sec. Comp. a someinsoluble remained at 300 sec. Not examined Comp. b some insolubleremained at 300 sec. Not examined Comp. c dissolved at 200 sec.Deposition found at 120 sec. Comp. d dissolved at 180 sec. Depositionfound at 150 sec.

Comparison Compound a

Comparison compound b

Comparison compound c described in DE 1946316

Comparison compound d described in Japanese Patent ApplicationNo.6-332127

EXAMPLE 8

In 1 mL of water was dissolved 10 mg of each of Compounds I-1, I-2, I-3,I-4, I-5, I-11, I-12, I-13, I-14, I-21, and I-22. The aqueous solutionwas diluted with methanol to give 5 mL of an aqueous methanol solution.

The resulting aqueous methanol solution was applied on to a filter papersheet, and the paper sheet was dried. Thus treated filter paper sheetwas irradiated with a UV light (λ=254 nm). All paper sheets emitted bluefluorescence.

1. 4,4′-Bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid compoundhaving the following formula:

in which each of L¹ and L² is an alkylene group having 2 to 8 carbonatoms which has an intervening ether bonding; each of R¹¹ and R¹²independently is hydrogen, methyl, ethyl, n-propyl, n-butyl, or2-sulfoethyl; each of R²¹ and R²² independently is hydrogen, methyl,ethyl, n-propyl, isopropyl, 2-hydroxyethyl, 2-hydroxypropyl,3-hydroxypropyl, 2,3-dihydroxypropyl, 2-sulfoethyl,2-(2-hydroxyethoxy)ethyl, 2-[2-(2-hydroxyethoxy)ethoxy]ethyl, phenyl,naphthyl, 4-hydroxyphenyl, 3,5-dicarboxyphenyl, 4-methoxyphenyl, and3-isopropylphenyl; and M is an alkali metal atom. 2.4,4′-Bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid compound ofclaim 1, wherein at least one of L¹ and L² is a divalent group which isrepresented by the following formula:—(CH₂CH₂O)_(n)CH₂— in which n is an integer of 1 to
 3. 3.4,4′-Bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid compound ofclaim 2, wherein n in the formula is 1 or
 2. 4.4,4′-Bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid compound ofclaim 1, wherein each of R¹¹ and R¹² in the formula independently is ahydrogen or methyl. 5.4,4′-Bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid compound ofclaim 1, wherein each of R²¹ and R²² in the formula independently ishydrogen, methyl, ethyl, isopropyl, 2-hydroxyethyl, 2-hydroxypropyl,3-hydroxypropyl, 2,3-dihydroxypropyl, 2-(2-hydroxyethoxy)ethyl,2-[2-(2-hydroxyethoxy)ethoxy]ethyl, phenyl, or 4-hydroxyphenyl.
 6. Anaqueous solution in which a4,4′-Bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid compound ofclaim 1 is dissolved in water.
 7. A method of brightening a surface ofmaterial with fluorescence which comprises applying onto the surface anaqueous solution in which a4,4′-Bis(1,3,5-triazinylamino)stilbene-2,2′-disulfonic acid compound ofclaim 1 is dissolved in water.